Correlation coefficient and path analysis of yield and yield attributing characters of rice (Oryza sativa L.) genotypes under reproductive drought stress in the Terai region of Nepal

Abstract

An experimental trial of nine rice genotypes was conducted in the Agronomy field of the Institute of Agriculture and Animal Science (IAAS) Paklihawa Campus under a randomized block design layout with three replications from July to November of 2022. The aim was to study genetic variability and analyze the character association of yield and yield-attributing components in rice genotypes and their direct and indirect effect on grain yield under reproductive drought stress conditions. Observations on days to flowering (50%), plant height, panicle length, panicle weight, number of grains/panicles, effective panicle/m², grain yield, and 1000 kernel weight were recorded. Grain yield showed a highly positive significant correlation with effective panicle/m² (0.713**), followed by plant height (0.347) and panicle length (0.289). The path coefficient analysis of different traits revealed the highest positive direct effect of the effective panicle per m² (0.748963), followed by panicle length (0.24145) and plant height (0.227505). The highest negative direct effect was shown by the number of grains per panicle (-0.31218). The experimental results revealed that the selection of trait-effective panicle per square meter would be most beneficial for the improvement of yield in rice genotypes facilitating selection and plant breeding programs.